In patients with foot and ankle trauma, surgery and postoperative mobilization are often delayed owing to swelling. The aim of this study was to assess whether continuous cryotherapy is better than standard therapy with intermittently applied cool packs. For continuous cryotherapy the Polar Care Model 500 (BREG) was used. From May to November 1993, a series of 40 patient (22 ankle fractures, 13 ruptured lateral ankle ligaments, 4 calcaneus fractures, 1 metatarsal fracture) were prospectively randomized to continuous or intermittent cryotherapy. After 24 h treatment the patients with continuous cryotherapy showed an average reduction of 34% in swelling around ankle, midfoot and forefoot. With intermittent cryotherapy the swelling was reduced by 18%. After 4 days of treatment in the postoperative period the swelling subsided by 43% with intermittent cryotherapy, as against 69% with continuous cryotherapy. Continuous cryotherapy proved to be highly effective in treating posttraumatic and postoperative edema. It therefore seems preferable to the therapy with cool packs regarded as standard hitherto.